Re: max question

On Tue, Apr 12, 2005 at 12:24:21 -0500, "A. R. Van Hook" <hook@lake-lotawana.mo.us> wrote:
> I have the following in a table:
>   oid   |   citkey   |  contby  |  contdate  | abcontinue |   ccdate  
> ---------+------------+----------+------------+------------+------------
> 5774835 | 04-0594703 |          |            |            |
> 5775325 | 04-0594703 | Attorney | 04/06/2005 | 6          | 03/07/2005
> 5776060 | 04-0594703 | Attorney | 05/04/2005 | 6          | 04/05/2005
> 5776067 | 04-0594703 | Attorney | 05/04/2005 | 6          | 04/05/2005
> 
> I am trying to pull rows that have the max. contdate. Why does the 
> following give more than 2 rows?
> ql "select oid,* from ccontinue where citkey ='04-0594703' group by 
> oid,citkey,contby,contdate,abcontinue,ccdate having max(contdate) = 
> contdate"

If you group by oid you are going to get a separate group for each row.
You haven't told us what you actually expect for output, so I don't
have specific advise for a query. However, you might find the Postgres
extension DISTINCT ON useful, depending on exactly what you want.

>   oid   |   citkey   |  contby  |  contdate  | abcontinue |   ccdate  
> ---------+------------+----------+------------+------------+------------
> 5776067 | 04-0594703 | Attorney | 05/04/2005 | 6          | 04/05/2005
> 5775325 | 04-0594703 | Attorney | 04/06/2005 | 6          | 03/07/2005
> 5776060 | 04-0594703 | Attorney | 05/04/2005 | 6          | 04/05/2005
> (3 rows)
> 
> thanks
> 
> 
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